Typewriter type bar action



July 20, 1954 L. B. HILL ET AL 2,684,145

TYPEWRITER TYPE BAR ACTION Filed Jan. 19, 1952 4 She'ets-Sheet lLAURENCE B. HILL.` GEORGE RKUNZELMAN BY M July 20, 1954 L. B. HILL ETAI- TYPEWRITER TYPE BAR ACTION 4 Sheets-Sheet 2 Filed Jan. 19, 1952GEORGE/p U. AroRs NEY July 20, 1954 1 B. HILL ET AL TYPEWRITER TYPE BARACTION Filed Jan. 19, 1952 FIC-P3 4 Sheets-Sheet 5 INVENTORS" LAURENCEB. HILL. GEORGE R.,KUNZELMRN AfToRNEY July 20, 1954 L. B. HILL ET ALTYPEWRITER TYPE BAR ACTION 4 Sheets-Sheet 4 Filed Jan. 19, 1952INVENTORS LAURENCE B. HILL GEORGE RKUN L Patented July 20, 1954 UNITEDSTAT -ATENT y OF FICE TYPEVVRITER TYPE BAB! ACTION- Application January19, 1952, Serial No. 267,234

20 Claims.

Thev invention relates to improvements in typewriter type bar actionsand, more particularly, to

vkeydriven and spring returned actions for acnormally are cumbent andarrayed in an arc` which curvesupward from the middle to the sides ofthe system.

Ther keys ofthe system ci' individual operating actions for such asystem of type bars are commonly arranged in stepped and straight banksor rows, usually four banks, which extend transversely of the typewriterat the front thereof. Such type bar and key systems present eX- tremelydifcultproblems with respect to attainment of such desirable ends assmooth and like rapid accelerationofthe printing strokes of all ofthetype bars withsharp printing impact and quicktype bar return, uniformoperatingdip or depression of all keys, uniformand light or easystarting touch for all keys, a like progressively increasing keyresistance to nger depression by all keys, and a like final cushioningabsorption of the momentum ,of a typists finger by each actuated key atthe end of the printing stroke of its associated type bar.

The invention provides an improved system of type bar actions andimproved individual type bar actions for the attainment of the foregoingprimary ends and other ends hereinafter pointed out.

Theimproved type bar action system also is characterized by provisionfor uniform-operation of all of the type bar actions ona straightuniversal bar, by .an improved arrangement of two sets of `type baraction returning springs, byimproved means whereby the typist may varythe key touch at will, by its compact and inexpensive construction, andby its adaptability for use in a typewriter in which the type bars arepivoted in a case shiftable segment and in a typewriter in which thesegment is disposed in arearwardly inclined plane forincreased-visibility of `the writing line and to reduce the overallheight of the machine.

In the accompanying drawings:

Fig. 1 is a fragmentary vertical sectional View of an otherwise knowntypewriter equipped with a system of type bar actions embodying theinvention in its preferred form, the View being taken medially of thesystem of actions on the lineI-l vof Fig..2; i

Fig. 2 is a fragmentary topvplan view of the typewriter with-.certainparts omitted, ,and-others broken away, rfor clarity of' illustration'`of features Vof the invention;

Figs. 3 and 4 are diagrammatic views illustrating the operationrespectively of one of the` type baractions at the middle'of the systemand'one of the actions adjacent a side of the system, both of whichactions have second bank operating keys;

Fig. 5 is a diagrammatic View on an enlarged scale four times that ofFigs. 1 to 4 and illustratingthe system of returning springs for the keylevers supporting the four different banks of keys;

Fig. 6 is adiagrammatic lView on the same scale as Fig. 5 showing howthe .actions are varied in accordance with the key bank in which theirkeys arelocated;

Fig. 7 is a diagrammatic view on a scale three times that of Figs. 1 to4 showing how the actions are varied in accordance with their locationsbetween the middle and sides of the system; and

Fig. 8 is a detail sectional view on the line 8 8 of Fig. 1 showingfeaturesof lthe means variably settable Yby a typist to uniformly andsimultaneously vary the touch of all of the keys.

The-improvements are shown embodied in a knownkind of typewriter havinga type bar segment` which is disposed in arearwardly inclined plane,which normally is positioned for lower case. typing, and which is caseshiftable downtypewriter having a type bar segment which is disposed ina vertical plane. So.y muchv of the known typewriter shown, as isnecessary to a clear understanding of the inventionnow will bedescribed.

The typewriter has aplaten roller Il) supported by a platen carriage(not shown) to travel end- Wise transversely of the typewriter above therear portion of av stationary main frame of the typewriter. The mainframe comprises vertically disposed left and right hand side plates Iland l2 and a rearwardly inclined cross plate I3 connected `to said sideplates with the upper edge of the cross plate underlying the platenroller. A type bar segment I4, having the usual arcuate fulcrurn rod l5about which the type bars I6 swing, and also having the usual radialguiding and spacing slots Il' for the type bars, is xedly heldin knownmanner toa rearwardly inclined and case-shiftable carrier plate orsegment support I8.. located. at the front face of the cross plate. The.carrier plate, the segment and the type bar fulcrum rod all' lie inrearwardly inclined planes parallel to that ofthe cross plate I3, saidplanes in the machine-shown being inclined rearwardly at an angle oftwelve and onehalf degrees to the vertical.

The carrier plate is supported, by means not shown, for downwardshifting from its normal position shown in ig. l to a lower position inthe same plane to condition the machine for upper case typing. Thenormal position of the carrier plate is determined by the engagement ofa stop I9 with a stop lug 23 which projects rearward from cross plateI3. Stop ld is carried by a lug 2l which projects rearward from thecarrier plate through a clearance aperture 22 in the cross plate.Downward shifting of the carrier plate is arrested by the engagement ofa stop 23 with the stop lug 2! on the carrier plate, the stop 23 beingoffset laterally relatively to stop i9 and carried by a lug 2li whichprojects rearwardly from the cross plate.

The type bars l normally are supported in cumbent slightly upwardly andforwardly inclined positions in an arcuate array which is determined, asusual, by the arcuate fulcruin rod, by the radially slotted segment andby an arcuate rest 25 for the type carrying arms of the type bars. Saidrest, as is usual in typewriters of the kind shown, is held to thesegment carrier plate by a pair of side arms to shift with the carrierplate, one of said side arms being shown at in Fig. l. ln the typewritershown, the rest 2d supports each of the type bars for a throw of 93degrees from rest to printing position. The main type carrying arms ofthe type bars each carry a lower case type and an upper case type, andeach type bar is extended rearward, as usual, beyond its fulcrum to forma type bar heel or short operating arm its for connection with anassociated key-operated action which exerts a forward pull on theoperating arm ltd to swing the type bar to printing position. Theoperating arms Hic are all of identical length and each makes the sameangle with the type carrying arm of the type bar of which it is a part.The segment supports the bars, as is usual in the kind of typewritershown, to print at a common printing point on a horizontal printing linewhich extends longitudinally of the platen roller somewhat above thelevel of the axial line of the platen roller. rhe two middle type barsof the system are located equidistant from the lowest point in the arcof the fulcrum rod l5 and from the medial vertical longitudinal plane ofthe machine containing the section line i-l in Fig. 2.

Certain features of the improved system of type bar actions which areknown in the art rst will be described.

The heel of each type bar is connected by a pivot 2l with the rear endof a different one of a system of pull links 28, and the forward end ofeach link 2S is connected by a pivot 23 to the upper end of a differentone of a system of sub-levers d@ of the third class. The sub-levers 33are fulcrumed at their lower ends on a common straight and horizontalfulcrum rod 3l. Fulcrum rod 3l is held in a rear portion of a sub-leverfulcrum bar 32 which extends across the lower portion of the main framebelow the system of type bars and is held to the main frame side platesil and I2 by screws 33, said rear portion of the bar being provided withvertical spacing slots 3d for the sub-levers 36. The two middle ones ofthe sublevers 36 of the System are located equidistant from the medialvertical longitudinal plane of the machine containing the section linel-l in Fig. 2, these two sub-levers being of equal length and 4 havingtheir link pivot connections 23 equidistant from fulcrum rod 3 l.

The sub-levers 3d are graded progressively upward in length from the twomiddle sub-levers to the two side sub-levers of the system and the upperportions of the sub-levers are bent laterally to conform with the arc ofthe type bar heels, so that all of the pivots 29 lie in an arc which isconcentric with the are of the type bar fulcrum rod and with the arc inwhich the pivots 2l lie. rihese arcs lie in parallel planes with the twopivots 2l, 29 of each link in substantially the vertical plane fore andaft of the machine. rlhe rear pivot 2l of each link is arranged to shifto points equal distances below and above a line normal to said parallelplanes in case shifting the segment respectively from and back to normalposition. The links 2S swing about their front pivots 2Q during casechanging, and the distance between pivots 2 and 29 is identical for allof these links.

First, second, third and fourth bank key levers 35a, 35h, 35C and 35d,respectively, of the system of key levers support the first, second,third and fourth bank type keys 33d, 35h, 35o and 35d, respectively, ofthe usual standard four bank keyboard. The key levers decrease in lengthfrom the first bank to the fourth bank, as usual, and all are fulcruniedat their rear ends on a common fulcrum rod lil' which is straight andextends horisontally across the machine. Rod 3l is carried by the upperportion of a key lever fulcrum bar which extends across the machine,which is held to the main frame side pla-tes by screws 3d, and which isprovided with vertical spacing slots d for the rear ends' of the keylevers. Adjacent the rear of the keyboard the key levers are spaced by akey lever guide comb lil which extends horizontally across the machine,which is held to the main frame side plates by screws 42, and whichsupports a straight horizontal cushioning stop 3, which stop extendstransversely across the machine and normally is abutted by the upperedges of the key levers to determine their returned or rest positions.

The improved features of the individual type bar actions and of thesystem of said actions now will be described with reference to thepreferred embodiment of the invention illustrated in the drawings.

To provide a more compact type bar action system located wholly forwardof the intermediate across plate i3 of the main frame, the key leverfulcruin bar 38 preferably is located closely in front of the lower partof said cross plate and extends across the lower portion of the mainframe below the system of type bar action links 28 and behind thesub-lever fulcrum bar 32. While the key lever fulcrum bar may be locatedadjacent the rear end of the main frame to there extend across the lowerportion of the frame, as is more common in the art, the location shownis preferred notwithstanding the fact that it results in substantialshortening of the key levers, one advantage of the improved system beingthat it makes possible the successful use of short key levers whileretaining a short uniform key dip and avoiding undue tilting of the keyson their printing strokes, as more fully hereinafter explained.

The sub-lever fulcrum bar 32 has a forward portion which carries astraight fulcrum rod ll-l that extends horizontally across the machineforward of and parallel to the fulcrum rod 3l and passes under theforward portions of the several type bars. Rod 44 is a common fulcrumfor a gesamt 'second'system of sub-leversfwhich are levers of therst'class andare engaged *in spacing slots 45 formedin said forward"portion of the vsublever' fulcrum bar. Each-offthese sub-levers is abellcrank and,v in the normal rest positions of the type bar actions,one arm of each bellcrank extends rearward and upward from the bellcrankfulcrum rod andthe other arm extends forward and downward Vfrom saidfulcrum rod. rIhese bellcranks are located behind the keyboard in a zoneforward ofthe system of sub-levers 3l) and are spaced along theirfulcrum'rod in accordance with the spacing of the sub-'levers 35i alongtheir fulcrum rod.

Each bellcrank has its normally rearwardly and upwardly extendingarme'connected to a different oner of the sub-levers 30 by aV different oneof a system of 'normally rearwardly and upwardly extending pull links41. These `links all are of identical lengths vand each link has apivotal connection'll with a different one of said bellcrank arms 46 anda pivotal connection 48 with a different one of said sub-levers 35i,these pivotal connections being arranged as more fully hereinafterexplained; For reasons hereinafter explained, the arms 46 of all of thebellcranks preferably are of identical size and shape and normally arein axial register across the machine.

Each key lever of the system of key levers is a lever of the secondclass; each key lever being connected intermediate its key and fulcrurnwith the normally forwardly and downwardly extending arm of a differentone of the system of bellcranks by a diiferent one of a system of pulllinks Eil. The pull links 50 all are of identical length, and each linkhas a pivotal connection l with a different one ofthe key levers and apivotal connection 52 with' a different one of said forwardly anddownwardly extending bellcrank arms. Each link 56 lnormally extendsforwardly and upwardly from its pivotal connection 5| to its pivotalconnection 52.

Preferably, and as shown, to save metal and still permit an arrangementof the sets of pivotal downward inclination, all of those bellcrankswhich are linkedv to the second bank key levers 35h have arms llbL ofidentical length and of identical normal forward and downwardinclination, all of those bellcranks which are linked to the third bankkey levers 35C have arms 46c' of identical length and of identicalnormal forward and downward inclination, and all of those bellcrankswhich are linked to the fourth bank key levers 35d have arms 46d ofidentical length and oi identical normal forward and downwardinclinationy but the lengths of the arms 46a, 46h, 6c and dtd, and alsotheir normal downward inclinations, are increased slightly in the orderof recitation of said arms, arms 46a being the shortest and having theleast normal downward inclination and arms 46d being the longest andhaving the greatest normal downward inclination. However, it will beobvious from the following description that all ofthe bellcranks of ietype bar action system may have those arms thereof which are linked tothe key levers by the system of links Evalso formed of identical sizeand shape and located in axial -register across theisystemvinthe normalpositionsrof the type Vthat of the bellcrankfulcrum rod Ml.

be such as to permit of the hereinafterdescribed arrangement Aof saidarms and links and the link pivots.

In typewriters having a/system of graduated sub-levers of the thirdclass connected by a'system of links to an arcuatesystem-of type bars toimpart printing strokes of identical amplitude to' the-type bars, theangles of -throwof thesublevers must-decrease asthe lengthsof thesublevers increase, and yall ofthe pivots connecting said' links to thesub-levers must swing through arcs of identical chordallength. Sincesaid` link pivots allv normally lie in a planeparallel lto thatcontaining the arcuate fulcrum rod for the type bars,- theymust swing topositions ina second and' parallel' plane to complete the printingstrokes of the type-bars. In the'machinefshown, link pivots 29 throwfrom the plane Pl tdthe plane P2, as indicated in Fig- '7, these planesibeing parallel to that containing the type-bar Afulcrum rod and beinginclined rearward at an angle of 121/2 degreesto the verticali. i Animportant feature of the invention resides in the arrangement of thebellcranks [i6-45a, the links 4l and the link pivots 43 and einiaccordance with a principle by which there is provided a system ofcongruent toggles by which the sub-levers 30 and pivots 29 areA sovdriven that all of the Apivots 29 vwill travelffrom'plane Pi to plane P2in time intervals of'identical duration and at identical acceleratingrates of speed in response to identical angular throws of the bellcranksat any 'singlespeed rate, and by which all of said toggles are connectedto sublevers Sli .between their fulcrum and pivots f2s at constantleverage ratio points affording an identical-purchase -of all toggleson' said sublevers. The aforesaid principle now will be described withparticular reference to the typewriter shown in the drawings wherein thetogglesy exert a pulling action on the sub-levers to impart printingstrokes to the type bars.

The link pivots 49 constitute the movable anchors of the toggles, andthe link` pivots 4-8 constitute the hinge pivots connecting the togglearms, which arms in turn comprise the links 4l andthe bellcrank armse,respectively. Arms le have a commoniixedly located pivotal anchor whichcomprises the bellcrank fulcrum rod M.' and is parallel to, and forwardof, thevfulcrum rod 3l of the sub-levers Sil. The axes of the pivots 9all lie on a cylindrical locus which is the periphery of ari-imaginarycylinder Cl whose axis is coincident with that of the bellcrank fulcrumrod 44. The pivots 4s normally lie on said locus at points between thesub-levers and bellcranks where the respective constant leverage arcsfor the graduated sub-levers 30 intersect said locus, said arcs beingstruck about lthe sub-lever fulcrum rod 3l and some of them beingindicated by the'reference letter A in Fig,k 7.- In the machine shown, aconstant leverage ratio of a fraction under 3 to l is selectedasdesirable, but of course a different ratio couldbe provided.v

The link pivots t8, or hinge pivots of the toggles, are all located on asecond cylindrical locus which is the periphery of a second imaginarycylinder C2 whose axis also is coincident with To provide pull toggles,the radius of the cylinder C2 is smaller than that of cylinder Cl.Pivots 48 are located on the locus or cylinder periphery C2 Aat thepoints where-straight lines of equal length will connect the axes ofeachpa'ifr' of pivots e8-'49,

By this arrangement, the eiective lengths of all links lll are identicaland the effective lengths of all arms d6 are identical. Also the toggleswill fold from congruent normal or starting conditions to congruentactuated or nnal folded conditions in actuating the sub-levers 35 toimpart printing strokes to the type bars.

While an effective link length may be selected which is equal to theradial distance between the peripheries of the two cylinders Cl and C2,and thereby afford congruent toggles which normally are fullystraightened and consequently normally would serve as anti-reboundtoggle locks for the type bars, it is preferred to select a greatereifective link length, as shown, so that said congruent toggles willhave congruent slightly folded normal conditions in which the hingepivots are displaced identical distances forward and upward fromstraight lines connecting the movable and fixed anchorages of therespective toggles. The preferred normal condition of the togglesirnproves the key touch. Pushing toggles could be provided` according tothe same principle by, for example, using a greater radius for cylinderC2 than for cylinder Cl, or by locating the axis 44 of these cylindersbehind axis 3 l, as will be obvious from the above explanation oftheembodiment of the principle in the typewriter illustrated in thedrawings.

A further important feature of the invention resides in the arrangementof the key levers, the bellcrank arms lla, Lith, itc and lld, the links59, and the link pivots 5I and 52 in accordance with a principle now tobe described. These parts are so arranged that the links lill and pivots5i and 52, and the portions of the key levers extending from link pivotsEl to the key lever fulcrum rod 3i' afford four sets or groups oftoggles, one for each bank of keys, to actua'te the bellcrank arms Caa.,45h, llc and 6d to impart printing strokes to the type bars. On the downstrokes of their acting keys these toggles act with rearward anddownward pulling actions on the -bellcrank arms to which they areconnected.

Each toggle includes a link 5G and that portion 0f a key lever whichextends from the key lever fulcrum to the link pivot 5i, the link 5@forming one arm of the toggle, said key lever portion forming the otherarm of the toggle, the pivot 5l forming the hinge pivot of the toggle,the pivot 52 forming the movable anchor' of the toggle, and the keylever fulcrum rod 3l forming a xedly located pivotal anchor for al1 ofthe toggles and lying parallel to the bellcrank fulcrum rod tl.

The parts forming the said four sets of actuating toggles for thebellcranks are arranged so that the links 5B form toggle arms ofidentical effective length, that said key lever portions form togglearms of identical effective length, and that all those toggles connectedto keys in the same key bank are congruent toggles which have congruentslightly folded normal or starting conditions and which fold farther tocongruent actuated or nal conditions on the down strokes of the keys.rlhe arrangement further is such that, although the lengths of the keylevers vary in accordance with the banks in which are located the keysthey carry, depression key strokes of like extent, like force and likespeed will rock the bellcranks through like angles at like speeds andlike rates of acceleration to effect complete printing strokes of thetype bars, and that all of the keys will offer the same graduallyincreasing resistance to depression.

To the attainment of the ends just above set forth, al1 of the pivots 5lare connected to the key levers of the four banks 35a, 35h, 35o and 35dso as to be equidistant from the key lever fulcrum rod Si' and normallyto be in axial alignment across the machine. All of the pivots 52 havetheir axes normally located on a locus which is the periphery of animaginary cylinder C3 (Fig. 6) whose axis is the axial line in which thepivots 5l normally are located. This locus intersects four constantleverage arcs Al (Fig. 6) which are of different radii and are struckabout the axis of 'the bellcrank fulcrum rod 44. There is thus one ofsaid arcs for each bank of keys.

The links 5G connected tothe first bank key levers 35a have their pivots52 connected to the bellcrank arms 56a to swing in that one of the arcsAl having the shortest radius, the links 50 connected to the second bankkey levers 35h have their pivots 52 connected to the bellcrank arms lhto swing in the next succeeding one of the aros Al, the links 53connected. to the third bank key levers Sile have their pivots 52connected to bellcrank arms itc to swing in the next succeeding one ofthe arcs Ai, and the links 5i? connected to the fourth bank key levers35d have 'their pivots 52 connected to the bell crank arms 8d to swingin arc Al having the longest radius.

All toggles of any group connected to key levers carrying keys in thesame bank thus have congruent slightly folded or downwardly brokennormal or starting conditions, the toggles in the group connected to thefirst bank or longest key levers being normally folded more than thosein the other three groups, the extent of normal fold decreasingl fromgroup to group of toggles connected to the second, third and fourth bankkey levers 35h, 35e and 35d in the order just recited. The toggle hingepivots 5i are each carried downward and rearward upon depression of itsconnected key lever on a cylindrical locus which is the periphery of animaginary cylinder C4 (Fig. 6) whose axis is coincident with that of keylever fulcrum rod 3l, the extentl of such movement being the same forall toggles connected to any one bank of key levers, and being least forrst bank key levers and increasing from bank to bank for the second,third and fourth bank key levers. The additionally folded final oractuated conditions of all toggles of any group connected to key leversof the same bank are congruent but the extent of added folding Varieswith the key lever banks to which the group of toggles are connected,being least for the toggles connected to first bank key levers andincreasing from key lever bank to key lever bank for toggles connectedto the second, third and fourth bank key levers.

By the above-described arrangement the key purchase on the bellcranksthrough the medium of the bellcrank actuating toggles progressivelydecreases on the down strokes of the keys since the links 5t on saidstrokes move nearer into parallelism with the bellcrank arms to whichthey are pivoted. The key purchase on the bellcranks through the mediumof said toggles also is the same for all keys regardless of the banks inwhich they are located, since the toggle purchase on the bellcranksvaries for each bank of key levers in direct proportion to relativelengths of the key levers of different banks, such toggle purchase beingleast for the rst bank, or longest, key levers and increasing for thesecond, third and fourth bank key levers.

From the foregoing description it will be obkey is depressed. Asindicated in Figs. 3

.l 9 served that, as indicated in Figs. 3 and 4, a full depression ofany type key at a constant rate will actuate the sub-lever 30 connectedvto said key, and consequently the type bar connected to that sub-lever,at a speed which accelerates throughout said key depression. It alsowill be observed that the rear portion of the actuated key lever actsthrough connected link 59 to impart an accelerated throw to the conneted belcranhand that this acceleration is greatly augmented by theaccelerating action of the arm 45 of the bellcrank and the link 41 whichconnects it to the sub-leVer'Sll. This compound,y cr two-stage,acceleraton assures a high speed type impact even for a relatively slowand easy depression of the key and thus enhances-the clarity of the typeirnpressions and permits the making of a maximum. number of good carbonCopies with a minimum key depression effort. lt further contributes tosuccessful use of short l-:ey levers with short key dip, since theextent of angular drive' of any sublever 3i! per equal increment of keydip is progressively and grcatly augmented as its actuating and 4,depression of a key at a constant rate and in, for example, four equalsteps, will cause the actuated bellcrank to rock through fourprogressively increasing steps and will cause the actuated sublever E@to rock through four still greater and progressively. increasing steps.The normal and final positions of the actions shown :in Figs. 3 and 4are indicated respectively in full lines and in dotted lines, and thetermini of the iirst, second and third steps of movement of the key,bellcrank and sub-lever .30 are indicated by correspondingly numberedrshort lines.

Further features of the invention comprise the two sytems of returningor retracting springs for the system of type bar actions, and theprovisions for adjusting the normal tension of the springs of the twosystems.

Different springs 53 of a system of helical tension springs of identicalsize, length and inherent power constitute the primary retractionsprings for the type bar actions. tend fore and aft of the machineparallel to the medial fore-and-aft vertical plane of the inachine, havetheir rear ends hooked in anchor holes E@ in the rearwardly inclinedupstanding flange portion 55o of a spring anchor bar 55, and

have their forward ends hooked in anchor holes 5S in the respectiveeuh-levers it@ below the laterally vbent upper portions of thesub-levers. Flange portion tichas arcuate upper edge curved upwardlyfrom its middle to its ends with the holes adjacent said edge andequidistant therefrom. The anchor holes 5d all are located in one andthe anchor' holesli all are located in a second arc. These arcs have thesaine radii, lie respectively in planes P3 and Ft (Fig. 7) parallel topiane Pi, are concentric with the arc inv-nich lie the pivots 2t at theupper ends of sup-levers and have their lowest points in the `medialfore-and-aft vertical plane of the typewriter. The twofanchor holes 56for any one sprinfr 53 occupy like positions in the arcs in which therespective holes are located, the holes 5t being spaced according to thespacing of the lor-fer portions of the sub-levers By the aforesaidarrangement of the system of springs 53, all of said identical springshave the sametension in the retractedpositions of the type bar actions7have their anchor holes t6 arranged to shift from plane Ps to a secondand parallel plane P5(Fig. 7) through arcs of like The springs 53 alleX- chordal lengths to stretch the-springs like extents on the printingstrokes of the type bars, and have their anchor holes 56 arrangedrelatively to the sub-lever fulcrum rod 3i at constant leverage ratiopoints for application of like effective power to the sub-levers. On theprinting stroke of any type bar, the stretching of the retractingsprinfy 53.01? the actuated type bar action is accelerated in directproportion to the acceleration of the type bar so thatthe acceleratedacquisition of kinetic energy by the type bar aids the stretching of thespring in such manner that a substantially constant resistance to keydepression is offered by the spring which contributes to ease andlightness of the key touch.

While the spring anchor yloar may be xed immovably to the main frame ofthe typewriter, it preferably is mounted for adjustment by the meansshown intol different selected positions to permit a typist to vary atwill the normal key touch by varying simultaneously and uniformly theextent to which all of the springs 53 are stretched in the normalreturned positions of the type bar actions.

To permit such adjustment of the normal stretch of springs 53, theanchor bar 55 is supported for adjustment in a path which is normal tothe planes PI, P2, P3, P4 and P5 (Fig. '7) thereby to shift the springanchors 55, while maintaining them in a plane parallel to the planes Pfland Ps in which the spring anchors 56 lie in the normal and actuatedconditions respectively of the type bar actions. To so support andadjust the anchor bar the following described means are provided, said`means being shown in Figs. 1, Zand 8 and set for minimum key touch.

Extending fore and aft of the typewriter, and riveted, or otherwise xed,to opposite ends of the anchor bar 55, are two end bars 5l having intheir rear ends slots 53 which extend normal to the planes Pl, F2, P3,Pd and P5 (Fig. 7) and also to the plane of flange portion 55a of theanchor bar. The key lever fulcrum rod 3l eX- tends through slots 53 tosupport the end bars El at their rear ends to shift in the aforesaidpath. To prevent lateral shifting of the slotted rear ends of the endbars, they are guided in slots 59 (Fig. 2) in the key lever fulcrum bar3d. To support the forward ends of the end bars to shift in said path,and to aiford ready detachment of the anchor bar with its end' bars,there is provided a rock shaft S6 which extends horizontally across thetypewriter and has reduced ends toc, and there are provided a pair ofbearing brackets Si which are xed to the sub-lever fulcrum bar 32 and inwhich the reduced ends of said shaft are journalled, a pair ofupstanding rock arms 62 and 63 iixed to said shaft, a pair of headedpivot studs 61% xed to said rock arms equidistant from said shaft, and apair of rearwardly extending slots 55 in the forward ends of the endbars 5l in which said studs 64 are engaged. Slots e8 and 65 are open atthe adjacent ends of the end bars til to permit ready demounting of theanchor bar.

The springs 53 urge the anchor bar forward to maintain the studs 4 atthe rear ends of slots Se. The rock arms S2 and 53, and the headed studs64, prevent lateral shifting of the forward ends of the end bars 5l ofthe anchor bar. The shaft is rockable to swing the rock arms 52 and 63downward and rearward dieren't distances from their limit position shownin the drawings and to carry the studs Gil rearward and downward in 1l apath substantially parallel to slots 58 and sub stantially normal to theplanes Pi, P2, P3 and Pf3.

To enable the typist to rock the shaft and rock arms, and to latch themin different selected positions to maintain the anchor bar inselectively adjusted positions, the left hand rock arm s2 is extendedupward to a point adjacent the top of the typewriter and is formed atits upper end with a finger-piece or handle portion 52a. rfhisnger-pieceextends through a foreand-aft slot Sii formed in a bracket 8l,this bracket being fixed to the top portion of the left hand Vside plateii of the main frame. Arm Q2 is a sheet metal arm having sufficientinherent resilience to maintain finger-piece 62a releasably latched inany desired one of a series of notches formed in the bracket 5i' alongthe right hand edge of slot t5, Vthe bracket shown having five notcheswith the setting indicating numerals l, 2, 3, 4 and 5 provided on thebracket opposite the respective notches. Preferably, arm 522 is formedwith a bent portion B2b which contacts the inner face of the main frameside plate i I intermediate the bracket 6i and the stud 64 which iscarried by said arm. This arrangement permits resilient flexing of theportion of the arm 62 above said bent portion @2b to unlatch thenger-piece 52a without straining or bending the end bar 5l with whichsaid stud 6ft on arm 62 is engaged. rThe end walls of slot 66 in bracket61 are abuttable by the finger-piece to determine the limits ofadjustment of anchor bar 55. In the position shown, the bar 55 isadjusted for light touch and anchors springs 53 so that they areslightly stretched while the several type bar actions are in normalreturned condition.

The system of auxiliary type bar action returning or retracting springs68 is provided to insure quick and full retraction of the key leversinto contact with the key lever stop d3 and to insure normal maintenanceof contact of the key levers with the stop. The auxiliary springs 68 areconstructed, arranged and anchored as is now to be described for actionof all of the springs with like effective force on the key levers andfor simultaneous and uniform adjustment to vary their effective force.For over-all lightness of key touch, it is preferable to use springs 68of a minimum force sufficient to slightly more than counterbalance theeifect of gravity on the key levers.

Springs 68 are helical coil springs all of the same size, strength andlength. Each spring is hooked at one end in an anchor hole 69 in the keylever it is to return, and is hooked at its other end in one of a seriesof anchor holes 'lil in an adjustable spring anchor bar li. Anchor holes"it are arranged in a horizontal row across the typewriter adjacent theupper edge of anchor bar 'Il and are spaced in accordance with thespacing of the key levers. The springs 63 extend downward and rearwardfrom holes 'i0 to holes t9. With the type bar actions all in normalposition, the anchor holes 6@ are so arranged that all holes 59 in keylevers carrying keys in the same bank are in axial register in a rowacross the typewriter, but the four rows of holes for the four diiferentbanks of key levers 35a, 35h, 35e and 35d are arranged progressivelycloser to the key lever fulcrum 3l in the just w recited order of saidbanks of key levers, as indicated in Fig. 5.

All four rows of holes t9, in the normal returned conditionY of thesystem of type bar actions, are located on a cylindrical locus C5 (Fig.5) the axis of which is the line on which the row of holes 'l0 islocated. Said rows of holes 69 are equally spaced on said locus indirect proportion to the respective effective lengths of the banks ofkey levers and are so located on said locus that a straight line can bedrawn from the line of the row of holes 'lil which will be normal to achordal line of said locus and will intersect the locus midway betweenthe rows of holes 69 in the nrst and fourth bank key levers and midwaybetween the rows of holes 69 in the second and third bank key levers.

in the machine shown, the anchor bar il extends across the typewriterbetween the key lever fulcrum bar 38 and the sub-lever fulcrum bar 32 ina rearwardly tilted position aiording a compact arrangement of thesebars. While thc anchor bar 'ii may be fixedly supported in various ways,it preferably is supported for slight adjustment of the position of therow of anchor holes it in a path at least substantially normal to achordal line of the locus of the rows of holes 59 intersecting the twooutermost rows of holes 9 which path will, of course, be normal to achordal line or the locus intersecting the two innermost rows of holes6s. For this purpose the rearwardly tilted anchor bar is provided alongits lower edge with a forwardly projecting flange Ha the straight frontedge of which is rockably seated in a horizontal groove or channel 'i2formed in the rear face of the sub-lever fulcrum bar 32. Adjusting andretaining screws 'i3 pass loosely through holes lli in bar il and arescrewed into holes tapped into the fulcrum bar 32 at the rear face ofbar 32, By screwing the screws 'i3 more or less into said holes, theanchor bar may be rockably adjusted. Springs 58 will maintain the anchorbar rocked against the heads of screws 13.

A further feature of the system of type bar actions above describedresides in the fact that it affords means for imparting uniform strokesto a straight universal bar for actuating a ribbon vibrator. Afstraightuniversal bar i5 depends from, and is fixed on, a rock shaft 'i5 whichjournalled at Ti in side plate ii and is journalled at 'i8 in a bracket'it xed to side plate l2. A rock arm Sii xed on said shaft carries auniversal bar return stop 8i which normally en gages a stop finger 82 onbracket 19. A universal bar return spring 83 is attached to a rock arm84 fixed on the shaft. The spring normally holds the universal barrocked into Contact with the rounded upper ends Lite of the bellcrankarms iii with stop ill engaged with stop iinger 32. Rock arm 84 isconnected by suitable linkage (shown in part at 85) to a ribbon vibrator(not shown) to actuate the vibrator at the type strokes.

We claim:

l. In a typewriter, a type action comprising a pivoted front strike typebar, an upstanding sub-lever of the third class connected at its upperend to the type bar to swing the bar into printing and rest positions, asub-lever of the nrst class forward of the third class sub-lever, a foreand aft extending key lever of the second class carrying its key at itsforward end, said sub-levers and key lever having their respectivefulcrum axes extending horizontally across the machine in parallelism, alink connecting the third class sub-lever between its ends with one armof the first class sub-lever to form with said arm a normally extendedtoggle arranged to fold to exert a continuously accelerating pull on thethird class sub-lever throughout the`printing strokes of the type bar,and a link connecting theothcr arm of thefirst class sub-lever with thekey lever forward of the keylever'fulcrurn axis `and second armsextending from a pivot parallel to that of the key lever, a nrst linkconnected by transverse horizontal pivots to the key lever and the rstarm of said iirst sub-lever, a second sub-lever extending upward from apivot between and parallel to those of the key lever and iirstsub-lever, a second link connected by transverse horizontal pivots tothe second arm of the rst sub-lever and to the second sub-lever be tweenthe ends of the second sub-lever, a front lstrike type bar pivotallymounted in the :typewriter and connected with the upper end of thesecond sub-lever to be swung throughra printing stroke of fixed lengthby downward rocking of the key lever, and spring means for restoring theaforesaid parts to a normal condition of rest in moving from which, intoa condition in which the type bar is in printing position, the firstlink `becomes decreasingly inclined to the key lever f and increasinglyinclined to the first arm of the rst sub-lever while the secondlinkbecomes decreasingly inclined to the second arm of the first sub-lever.

3.In a typewriter, a type action comprising a key lever and first andsecond sub-levers each rockable aboutV a different one of three parallelhorizontal fulcrum axes which extend transversely of the typewriter,said first sub-lever having rst and second arms and said second sublevervhaving a single and upstandingfarm, va first link connected byhorizontal transverse pivots to the key lever between the key and thefulcrum axis of the key lever and to the rst arm oi the iirst-sub-lever,a second link connected by horizontal pivots to the second subleverbetween the upper end and the fulcrum axis of that sub-lever and to thesecond arm of the first sub-lever, and a normally cumbent front strikepivoted type bar having a type carrying arm and a heel portion-,athirdilink having a forward end pivotally connected to'the upper end ofthe second sub-leverl and a rear end pivotally connected to the heelportion of the type bar, the pivots of the rst link being so arrangedthat a normal inclination of said link to the key lever decreases and anormal inclination of said link to the rst arm of the first sub-leverincreases throughout printing strokes of the type bar in response todownward rocking movements of the key lever, and the pivots of thesecond 'link being so arranged that a normal inclination of said link tothe second arm of the rst sub-lever decreases throughout printingstrokes of the type bar in response to downward rocking movements of thekey lever.

4. A typewriter, as claimed in claim 3, wherein the type bar carrieslower and uppercase type, and wherein means are provided for bodily caseshifting the type bar relatively to said key lever and to the twosub-levers into positions for lower Cil .ably connecting the key leverssupporting keys and 4upper case typing, in both of which positions thepivotal connection of the third link with the heelportion .of the typebar is equidistant from the pivotal connection of said link with theupper end of the second sub-lever.

5. A typewriter having a system of type actions which comprises a systemof type keys arrayed across the typewriter in a plurality of fore andaft spaced and horizontal transverse rows, a system of key leverscarrying said keys and extending rearwardto a common straight andhorizontal transverse fulcrum axis, a system of sub-levers ulcrumed atone end of each sublever to rock about a common fulcrum axis parallel tothat of the key levers, said sub-levers vincreasing in length from themiddle to the sides of the sub-lever system and having their other endsnormally arrayed in an arc across the typewriter, a system of pvotedtype bars normally arrayed in an arc concentric with that of said otherends of the sub-levers and connected with said ends for movement throughlike printing strokes to a common printing point, a system of congruentand parallel toggles extending from the sub-levers to a common fulcrumaxis parallel to those of the key levers and sub-levers, said toggleshaving hinge pivots and anchoring pivots to the sub-levers which areequally spaced and respectively normally located on different ones oftwo cylindrical loci concentric with the toggle iulcrum axis, saidanchoring pivots of said toggles being connected to the sub-levers atunivform leverage points, and connections between the respective keylevers and toggles for actuating the toggles to the same extent insub-lever accelerating direction by equal depressions of the respectivekeys to drive the respective type bars through complete printingstrokes.

6. A typewriter having a system of type actions which comprises a systemof key levers extending orward from a straight and horizontal.transverse fulcrum axis and supporting their keys in fore and aftspaced transverse rows, a system of normally cumbent and forwardlyextending type bars pivotally supported in an .parallel to that of thekey levers, a system of links each having a pivotal connection with onearm of a diirerent one of the iirst class sublevers and a pivotalconnection at a constant leverage point with a diierent one oi the thirdclass sub-levers, the two pivotal connections of .all of said linksbeing equally spaced and aru ranged on diiierent ones or" twocylindrical loci .which are concentric with the iulcrum axis of the rstclass sub-levers, and a system of links variin diierent rows to theother arms of said iirst class sub-levers to rock those sub-leversthrough angles of the same amplitude per unit depth of key depression.

i7. A typewriter having a system of front strike type actions comprisinga system of key levers extending forward in the typewriter from astraight and horizontaltransverse iulcrum axis and presenting'fore andaft spaced horizontal rows of keys parallel to said axis, a system ofupstanding sub-levers of progressively increasing heights from themiddle to the sides of the system and having a horizontal fulcrum axisat their lower ends parallel to and forward of that of the key levers, asystem of pivoted front strike type bars connected with the upper endsof the sub-levers to be swung through printing strokes of identicalamplitude by forward movements of the upper ends of the sub-leversthrough arcs of identical chordal amplitude, a system of congruenttoggles radiating from a xedly located fulcrum axis parallel to andforward of those of the key levers and sub-levers to pivotal connectionswith said sub-levers located at uniform leverage points on thesub-levers and on a cylindrical locus concentric with said fulcrum axisof the toggles, all of said toggles normally being identically andsubstantially fully straightened, and means connecting the key leversand toggles for folding of the toggles identical extents by identicaldepression strokes of the keys.

8. A typewriter, as claimed in claim 7, wherein the means connecting thekey levers and togy gles includes means for equalizing the initialpurchase on the toggles of keys in different key rows.

9. A typewriter, as claimed in claim 8, wherein the means connecting thekey levers and toggles further includes means to progressively olecreasethe key purchase on the toggles through the depression strokes of thekeys.

10. A typewriter having a system of front strike type actions comprisinga system of upstanding sub-levers having their upper ends arranged in anarc which curves upwardly from the iniddle toward the sides of thetypewriter and having at their lower ends a common straight andhorizontal transverse fulcrum axis, a system of pivoted front striketype bars connected with the upper ends of the sub-levers to be swungthrough printing strokes of identical amplitude by forward movements ofthe upper ends of the sub-levers through arcs of identical chordalamplitude, a system of congruent toggles each having first and secondmembers connected by a hinge pivot, the first members of the toggleshaving a ixedly located common fulcrum axis forward of and parallel tothat of the sub-levers and having extensions forward oi their fulcrum Yaxis, the second members of the toggles having pivotal connections tothe sub-levers at uniform leverage points on the sub-levers whichnormal- 1y are located on a cylindrical locus concentric with thefulcrum axis of the first toggle members, the hinge pivots of thetoggles normally being located on a second smaller cylindrical locusconcentric with the first mentioned locus, a second system of congruenttoggles having pivotal connections at one end to said extensions of thefirst toggle members of the other system of toggles and extendingrearward therefrom to a common xedly located fulcrum axis parallel tothat of said first members of the other system of toggles, and a systemof type keys carried each by a diiferent toggle of said second system oftoggles for folding the latter toggles as the keys are depressed.

l1. A typewriter, as claimed in claim 10, in which the keys are arrangedin fore and aft spaced straight and horizontal rows, and wherein thepivotal connections of the toggles of the second toggle system with saidextensions of the rst toggle members of the other toggle system arearranged to decrease the normal initial purchase of said toggles on saidextensions in accordance with the increase of the distance of the keyrows from the rear one to the front one of said rows from the fulcrumaxis of the toggles of the second system and also to progressivelydecrease the initial toggle purchase on said extensions throughoutdepression strokes of the keys.

12. A typewriter having a system of front strike type actions comprisinga system of first, second, third and fourth bank key levers of thesecond class, a system of fore and aft extending sub-levers of the firstclass, a system of upstanding sub-levers of the third class increasingin height from the middle to the ends of the system, means affordingcommon straight and hori- Zontal transverse fulcrum axes for the threelever systems with the axis for the system of upstandng sub-leversintermediate those for the key levers and the fore and aft extendingsublevers, a iirst system of links of identical lengths having pivotalconnections with the upstanding sub-levers and the rear arms of the foreand aft extending sub-levers, the pivotal connections of said links withthe upstanding sub-levers being located at uniform leverage points onsaid sub-levers and on a cylindrical locus concentric with the axis ofthe fore and aft extending sublevers, the pivotal connections of saidlinks with the rear arms of the fore and aft extending sub-levers beinglocated on a smaller and concentric cylindrical locus, a second systemof links of identical lengths having normally axially aligned pivotalconnections with all of the key levers and having pivotal connectionswith the forward arms of the fore and aft extending sub-levers whichnormally are axially aligned for those links connected to any one bankof key levers but which normally are located at distances from thefulcrum axis of the fore and aft extending sub-levers which increase forlinks connected to each bank of key levers following the first bank, anda system of pivoted front strike type bars connected with the upper endsof the upstanding sub-levers to be swung through printing strokes bydepression strokes of the key levers.

13. A typewriter, as claimed in claim 12, wherein the type bars areconnected to the upstanding sub-levers by links of like lengths, andwherein the system of type bars is mounted for case shifting movementsrelatively to the three lever systems.

14. A typewriter, as claimed in claim 12, wherein the two systems ofsub-levers and the two systems of links both extend across thetypewriter and below the system of type bars, the fulcrum axis of thekey levers extends across the typewriter and below the system of typebars, and the keys of the four banks of key levers extend in rows acrossthe typewriter adjacent the system of type bars.

15. A typewriter, as claimed in claim 12, having a system of type actionreturning springs of like lengths and power anchored at one end to theupstanding sub-levers at uniform leverage points on said sub-levers andnormally extending parallel to each other, and also having meansstationarily anchoring the other ends of said springs, the anchored endsof the system of springs normally lying in two parallel planes.

16. A typewriter, as claimed in claim 15, havhand lever adjustable meansfor shifting the plane of the stationarily anchored ends of the springstoward and from the plane of the other anchored ends of the springs andin a path normal to the latter plane.

17. A typewriter, as claimed in claim 16, having for the key levers asystem of counterbalancing springs of like length and power which arestationarily anchored on a line .parallel to the fulcrum axis of the keylevers and are an- Choi-ed to the respective banks of key levers atpoints on a cylindrical locus concentric with said line, the springanchor points to the key levers Y of different 1oanks approaching thekey lever axis in order from the rst to the fourth bank key levers.

18. In a typewriter, a system of front strike pivoted type barssupported for identical printing strokes from normally cumbent positionsin an arcuate array of said bars that rises toward the sides of themachine, a system of type key levers extending rearward from a multiplerow keyboard to a straight and horizontal transverse key lever fulcrumaxis, a rst system of sub-levers upstanding from a fulcrum axis par--allel to that of the key levers and having their upper ends arrayed inan arc concentric with that of the type bar array, means connecting theupper ends of said sub-levers with the type bars to swing the type barsthrough printing strokes and return strokes, a second system ofsubdevers having front and rear arms extending from a rulcrum axisforward of and parallel to that of the first system of sub-levers, asystem of links having identically spaced horizontal pivotal connectionswith the upstanding sub-levers and the rear arms of the othersub-levers, said pivotal connections being located on two cylindricalloci which are of different diameters and are concentric with thefulcrum axis of the second system of sub-levers, the pivotal connectionswith the upstanding sub-levers being located on the locus of greaterdiameter and at uniform leverage affording points on said upstandingsublevers, connections between the key levers and the forward arms ofthe second system of sublevers for rocking said arms downward bydepression strokes of the key levers, the rear arms of the second systemof key levers being of identical size and shape and normally being inregister across the typewriter, and a straight universal bar extendingacross said identical sublever arms and supported for actuation by saidarms on depression strokes of the key levers.

1S. A typewriter having a system, of type actions comprising a system ofupstanding sublevers rockable about a common straight horizontal fulcrumaxis which extends transversely of the typewriter with the upper ends ofthe sublevers normally arrayed in an arc which curves upwardly towardopposite sides of the typewriter, a system of pivoted front strike typebars connected with the upper ends of the sub-levers to be swung throughprinting strokes of identical amplitude by forward movements of theupper ends of said sub-levers through arcs of identical chordalamplitude, a system of congruent parallel toggles extending from acommon fixed fulcrum axis which is forward of and parallel to that ofthe sub-levers to pivotal anchorages which are located at uniformleverage points on the respective sub-levers, said toggies normallybeing in identically extended conditions in which their hinges arelocated on one cylindrical locus concentric with the toggle fulcrurnaxis and their anchorages to the sub-levers are located on a second andconcentric cylindrical locus of larger radius, and a system ofdepressible keys connected with the respective toggles to swing thetoggle hinges upwardly and forwardly about the toggle fulcrum axis onthe depression strokes of the keys to impart printing strokes to thetype bars.

20. A typewriter having a system of type actions comprising a system ofupstanding sublevers rockable about a common straight horizontal fulcrumaxis which extends transversely of the typewriter, said sub-levershaving their upper ends normally arrayed in an arc which curves upwardlytoward opposite sides of the typewriter, a system of pivoted frontstrike type bars connected with the upper ends of the sublevers to beswung` through printing strokes of identical amplitude by forwardmovements of the upper ends of said sub--levers through arcs ofidentical chordal amplitude, a system of congruent and parallel toggleshaving a common xed fulcrum axis parallel to the sub-lever axis, saidtoggles normally being identically and substantially full straightenedand having pivotal anchorages to the sub-levers at uniformi leveragepoints on the respective sub-levers which normally lie on a cylindricallocus which is concentric with the xed fulcrum axis of the toggles, asystem of key levers which extend forward from a fixed fulcrum axisparallel to that of the toggles and support a plurality of fore and aftspaced rows of keys at the front of the typewriter, and a system ofindividual connections between the key levers and toggles for foldingthe toggles identical extents at identical accelerating speed rates bydepression strokes of the keys of identical extents and identicalconstant speed rates.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,028,214` Hess June 4, 1912 1,034,154 Smith July 30, 19121,689,888 Myers et al Oct. 30, 1928

